Publication Information

Abstract

Abstract does not appear. First page follows.

Previous investigations(1), (2), (3) on the use of paper as a mulch in contrast to soil mulches have dealt mainly with
the effect on crop growth and crop yields. Investigations are now under way regarding
the effects of such paper covering on the temperature and moisture conditions of the
soil, and also on the most desirable kind of paper to use with particular regard to
color, weight, durability, and need for perforations.

By the use of an unperforated black paper mulch at Berkeley in 1924, Shaw(4) found that the soil at a depth of three inches averaged about 0.42° F warmer than
at a similar depth in the soil-mulched plots. Hartung(2) in the pineapple fields of Hawaii obtained higher mean soil temperatures at a depth
of three inches in areas covered with grayish brown paper mulches than in unprotected
soil. In his summary he states that “paper mulch maintains a mean soil temperature
in the upper 3-inch layer of soil during the cool season in the localities given,
from 3 to 4.5 degrees Fahrenheit above that of nonpaper covered soil; provided the
mulch paper is dark, preferably black in color.” Although the standard mulch paper
which Hartung used presented a “greyish brown appearance,” he nevertheless recommends
black paper. Stewart(5) and his co-workers in Hawaii found that on clear days the areas covered with black
paper were from 12° to 15° F warmer during the day, and from 4° to 5° F warmer during
the night.

Literature Cited

[1] Eckart Chas. F. How thermogen enhances the growth of plants 1-29. 1923. San Francisco: Published by author.